AB1677 VALIDATION ANALYSIS OF THE PHYSICIAN GLOBAL ASSESSMENT (PGA) SCALE IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS INCLUDED IN RELESSER-PROS REGISTRY
Authors: L. Cáceres Martín, I. Rua-Figueroa, N. Jiménez, M. Galindo-Izquierdo, J. Calvo-Alen, R. Menor-Almagro, A. Fernandez-Nebro, J. Martínez-Barrio, E. Rodríguez Almaraz, E. Uriarte Isacelaya, E. Aurrecoechea, N. Mena-Vázquez, J. M. Senabre-Gallego, J. A. Bernal, A. Pérez Gómez, V. Torrente, J. Narváez, C. Sanguesa, M. Arévalo, M. Freire González, C. Moriano, C. L. Iñíguez, E. Tomero Muriel, J. L. Andreu, M. J. Garcia Villanueva, T. Cobo-Ibáñez, G. Bonilla, N. Lozano Rivas, L. Horcada, C. A. Montilla-Morales, L. Expósito, E. Ruiz Lucea, J. Eloy Oller, A. Pecondon-Español, J. Loricera, F. J. Nóvoa Medina, E. Salgado Perez, T. C. Salman Monte, A. Muñoz Jimenez, J. J. Fragío Gil, J. M. Pego-Reigosa
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> There is currently no agreement on which scale should be used to evaluate systemic lupus erythematosus (SLE) disease activity. PGA describes an instrument for a global assessment of the degree of disease activity by the clinician and it is generally regarded as the gold standard. Despite its wide use and some degree of validation, the psychometric properties of this scale have not been formally evaluated and it is unclear whether more commonly used analogue scales for global assessment of rheumatic disease activity by the clinician, such as a VAS from 0 to 10, would be more appropriate. <h3>Objectives</h3> The aim of this study was to assess the construct and criterion validity of the physician global assessment (PGA), from 0 to 10, in a wide sample of SLE patients from Spain, analyzing the correlation with SLEDAI, health-related quality of life (QoL) and its ability to predict damage in order to promote its more widespread use. <h3>Methods</h3> An observational, longitudinal and prospective design was carried out. A total of 1821 patients from the RELESSER-PROS registry and data from 5 annual consecutive visits were tested. Activity was estimated using PGA from 0 to 10 transformed to AM-PGA (mean-adjusted PGA)(AMP), and AM-SLEDAI (mean-adjusted SLEDAI)(AMS); damage through SLICC/ACR Damage Index (SDI) and QoL by means of EuroQoL 5D y Lupus Impact Tracker (LIT) tools. The correlation between indices and their ability to predict damage progression (defined as any increase of 1 unit in SDI from baseline) and QoL was calculated. Pearson's or Spearman's correlation coefficients were calculated for each variable in comparison. <h3>Results</h3> The correlation between PGA and SLEDAI was higher for lower PGA values and there was a correlation between AMP and AMS, ranging 0.4 and 0.5. AMS explains a percentage of AMP variation that rises to 27% when introducing the number of domains affected by SLEDAI, in non-parametric model. AMS and AMP values are discrepant, especially for patients with low AMS and high AMP values and differs significantly in 3 domains: serological, neuropsychiatric, and renal. Excluding patients from the model, who were marked as discrepant, a significant linear relationship between AMS and AMP, around 0.5 shown up. Regarding damage, the correlation between AMP, AMS and SLICC/ACR (SDI) explained only 13% of SDI variance. SLEDAI accounts for a higher percentage of SDI variance than PGA (10.18% vs. 5.65% in smoothed model), but both do it independently. Analysis the discrepant and non-discrepant patients showed a fairly discrete linear relationship, less than 3%, between the AMS and AMP with the LIT and the EQ5D6 only for the non-discrepant patients. <h3>Conclusion</h3> The correlation between PGA and SLEDAI is low and both should be used together. PGA could improve the assessment of disease activity and its use adds the possibility to improve damage prediction. <h3>Reference</h3> <b>[1]</b> Chessa E, Piga M, Floris A, Devilliers H, Cauli A, Arnaud L. Use of Physician Global Assessment in systemic lupus erythematosus: a systematic review of its psychometric properties. Rheumatology (Oxford). 2020; 59(12):3622-3632. <h3>Acknowledgements</h3> "Research Unit of the Spanish Society of Rheumatology. Spanish Foundation of Rheumatology financial supporting, through the research intensification grants program. GSK financial supporting" <h3>Disclosure of Interests</h3> None Declared.